The present invention relates to a system and method for transferring calls in a wireless communications system, and more particularly to a system and method of negotiating bearer attributes while transferring a call.
A “call transfer” is a common phone service in which one of the parties can transfer the call from one telephone to another telephone. Calls can be transferred to wireless communications devices, either from landline communication devices or from other wireless communications devices.
However, wireless communications devices can vary in their ability to receive and transmit media other than voice. Older wireless devices, such as 2G cellular phones, can only provide voice communication and cannot receive and transmit media other than voice (e.g. multimedia). Newer wireless devices such as 3rd Generation Partnership Project 3GPP and 3GPP2 devices can handle various media such as data, text, special application, video, etc., as well as voice communications.
Known systems and methods of transferring calls between devices having different media handling capabilities can result in not exploiting the functionality/capabilities of the devices. The media description of the devices involved in the original call defining their media handling capabilities is passed on to the device receiving the transferred. For example, the media description of a call transferred from a 2G device to a 3G device is not changed during the transfer to accommodate the range of media handling attributes of the 3G device. Therefore, the 3G device is limited to the media attributes established in the original call and may not be able to utilize it's full range of media handling attributes.
It is desirable to enable a wireless device receiving a transferred call to fully utilize it's media handling attributes.